Centrifugal pump assembly



June 28, 1966 H. LOGUE rm.

CENTRIFUGAL PUMP ASSEMBLY 4 Sheets-Sheet 1 Filed Feb. 6, 1964 INVENTORS.Leland H. Logue Emile P Anderson BY 7 uw g 5W ATTORNEYS June 28, 1966 L.H. LOGUE'. ETAL 3,257,956

GENTRIFUGAL PUMP ASSEMBLY Filed Feb. 6, 1964 4 Sheets-Sheet 2INVENTORS'. I 60 Leland H. Logue Emile R Anderson BY ATTORNEYS June 28,1966 L. H. LOGUE ETAL 3,257,956

CENTRIFUGAL PUMP ASSEMBLY Filed Feb. 6, 1964 4 Sheets-Sheet 5 INVENTORS.Leland H. Logue Emile I? Anderson ATTORNEYS June 28, 1966 L. H. LOGUEETAL 3,257,956

CENTRIFUGAL PUMP ASSEMBLY Filed Feb. 6, 1964 4 Sheets-Sheet 4 i l i 44xl l L l l n 340 f w W///////l\ 5% L e/and .XE L ZS g h I l EmI/e RAnderson FI 11 a 7 %%WM ATTORNEYS 3,257,956 QENTRIFUGAL PUMP ASSEMBLYLeland H. Logue and-Emile P. Anderson, Denver, (2010., assignors toDenver Equipment Company, Denver, Colo., a corporation of Colorado FiledFeb. 6, 1964, Ser. No. 343,049 12 Claims. (Cl. 103-103) This inventionrelates to centrifugal pumps and to a mounting arrangement for thecomponents of a centrifugal pump operating assembly.

When centrifugal pumps are installed in an operating location, a primemover such as an electric motor will be mounted in fixed relation to thepump, and the drive usually employs V- belt, or similar transmission,inclusive of a sheave on the shaft supporting an impeller or runnerWithin the pump casing. Inlet and discharge lines are secured on thepump casing and the entire assembly becomes an essentially permanent orfixed installation.

When such pumps are used as sand pumps or acid pumps they are providedwith liner members to prevent excessive wear on or damage to the casinginterior, and these liners require periodic inspection and replacementor repair. The impeller also receives considerable wear requiringinspection and occasional replacement. Each time the pump unit requiresinspection or repair, all exterior connectionsmust be removed, and thepump casing opened to provide access to its interior. Usually, thisinvolves a considerable amount of time and labor for inspection orbefore worn parts are removed and replaced,

. and the unit is reassembled.

It is an object of the present invention to provide a base mounting fora centrifugal pump assembly which is normally fixed or stationary butincludes a movable portion permitting separation of pump components forquick and easy inspection and replacement.

Another object of our invention is to provide a simple, durable andefficient connector for the discharge line of a pump which normallyholds the line in sealed connection with an opening in the pump casing,and which may be actuated by simple manipulation to separate the linefrom the casing when the latter is to be opened for inspection orrepair.

A further object of our invention is to provide a sectional volutecasing for a centrifugal pump, which sections are securely joined duringoperation of the pump, and may be easily separated for inspection orrepair of interior components of the pump.

Other'objects reside in novel details of construction and novelcombinations and arrangements of parts all of which will be set forth indetail in the course of the following description.

The present invention provides several innovations in the constructionand installation of centrifugal pumps, all of which simplifyinstallation and maintenance of the pump and reduce out of service timeand labor, particularly in connection with inspection or replacement ofinterior components of the pump.

One of the innovations provides a base structure adapted for mounting asa permanent plant installation, and including upper platform members onwhich'the pump and associated operating members are supported. Oneplatform member is arranged for movement toward and away from the otherto assist inspection and maintenance of internal components of the pump.In one'application, the motor or other drive components will be mountedon the fixed platform member and the pump casing will'be mounted on themovable member so as to permit separation of a cover portion of the pumpcasing from the remainder of said casing for exposing its interior andto permit removal of internal components. After reassembly of theinternal components, the plat- United States Patent form carrying thecasing is moved to close the pump and permit it to resume operation.

Another application has the pump casing secured on the fixed platformand the drive' shaft, shaft bearings, motor and transmission systemsupported from the movable platform, whereby such components can bemoved away from the pump casing to expose its interior. The latterarrangement usually is utilized with smaller size pumps. having atwo-piece volute split in a vertical plane and in which the motor ismounted in an overhead position and maintains the transmission drive infixed relation to the shaft during such movement. For large sized pumpshaving a one-piece volute and .requiring heavy motors, the firstdescribed arrangement is preferred.

Still another embodiment provides a sectional volute casing having aflanged external inlet on one section and a split flanged externaloutlet with an eccentric actuated connector supported from one splitsection. The split section containing the inlet and the connector ismounted on the fixed platform member and the other section and driveassembly are supported from the movable platform member.

The inlet and discharge line connectors also utilize novel structuralarrangement permitting fast coupling and uncoupling operations. This isof particular advantage because the liners extend from the pump interiorwith flanged portions seated onthe inlet and outlet flanges and areclamped into liquid sealing relation by the 'connectors. The connectorspermit the associated line to be held substantially in its normaloperative position while it is separated from the pump casing as inmoving the casing in the operations referred to above.

Thus, it will be apparent that in addition to providing a satisfactorybase support for the initial pump installation, the base member of thisinvention greatly assists in pump inspection and servicing, particularlyin reducing shut-down time and labor costs thereof.

The practice of our invention will be described with reference to theaccompanying drawings illustrating typical embodiments. In the drawings,in the several views of Which'like parts bear similar referencenumerals,

FIG. 1 is a side elevation, partially broken to show interior parts, ofone embodiment of a centrifugal pump installation utilizing features ofour invention;

FIG. 2 is an end elevation of the pump installation shown in FIG. 1;

FIG. 3 is a side elevation similar to FIG. 1 and drawn to a reducedscale illustrating the separation of the platform members of the baseand the resulting exposure of the interior of the pump casing shown inFIG. 1;

FIG. 4 is a side elevation of another embodiment of centrifugal pumpinstallation with members separated as in condition for inspection orreplacement of parts;

FIG. 5 is a side elevation similar to FIG. 4 but with an oppositearrangement of fixed and movable platform supports;

FIG. 6 is a vertical nector of the present invention which is adapted'for use as the outlet connector with a sectional volute casing assembly;

FIG. 7 is a top plan view of the connector installation 1 shown in FIG.6;

FIG. 8 is a top plan view of the outlet connector assembly shown in FIG.1;

FIG. 9 is a section taken along the line 99.of FIGL S,

and drawn to an enlarged scale;

FIG. 10 is a vertical section through the outlet connector assembly ofFIG. 8 in the line separating position required for separation of themovable and stationary volute casing portions; and

FIG. 11 is a section similar to FIG. 10 illustrating the liquid sealingaction when the pump is operating.

section of one form of line con- The pump installation shown in FIG. 1is a preferred arrangement for smaller size pumps having sectionalvolutes and comprises a bed or base portion 12 adapted for attachment orpermanent fastening to a floor or other supporting structure 13 as bybolting (not shown). The bed 12 has parallel, upstanding side members14. Sectional deck or platform members 15a and 15b are supported on thetop surfaces of sides 14 and have flanged or guide portions 16 looselyfitted on said sides. The member 15b is mounted for movement toward andaway from member 15a, and a screw 17 threaded in a stationary block 18secured to a transverse portion 120 ofbed 12 and having fixedconnections 19 with bearing members secured on platform 15b provides therequired movement of platform 15b, preferably by attaching an impactwrench to a headed member 20 on the external end of screw 17.

Platform member 15a has a pedestal 21 bolted on its top surface as shownat 22 which provides fixed support for one section 23a of a Volutecasing which fits against another volute section 23b supported from thepump pedestal 24 held on movable section 15b as by bolts 26. Bolts 25hold the sections 23a and 23b in fluid sealed relation while the pump isoperating and are removed when the pump is to be opened for inspectionor repair.

Volute section 23a has a central inlet opening 27 (FIG. 2) formed by aflange portion 28 of section 23a mounted on a face plate 29, and aconnector member 31 abuts flange portion 28 and is secured thereon bybolts 32. Member 31 carries an inlet line 33 on its exterior surface.Face plate 29 is held on section 23a by bolts 30. Section 23a also has aportion 34a providing an outlet for the pump discharge which has acompanion part 34b on section 23b.

Pump pedestal 24 has an adjustable overhead platform 35 supporting aprime mover such as an electric motor 36 having a sheave 37 carrying aplurality of V-belts 38. The pedestal 24 also supports a bearing housing39 in which a shaft 40 is supported for rotation and a sheave 41 on theshaft is driven by the V-belts 3S. Shaft 40 extends through a gland 42on section 23b of the casing and supports an impeller (not shown)interiorly of the casing. Section 34b of the outlet portion carried onsection 23b cooperates with companion section 34a to form a flangedoutlet portion on which a discharge line 43 is secured by a connectormember 44, the details of which will be set forth in the followingdescription.

When the pump is to be opened after a period of operation, the bolts 25and 46a are removed and bolts 46 are loosened. The inlet line is securedon the stationary casing section 23a, and it is unnecessary to detachconnector 31 for inspection and line 33 remains in place. However,discharge line 43 must be detached from its seated position to permitwithdrawal of casing section 23b from section 23a. A preferred type ofconnector 44 is shown in FIGS. 8, 9, 10 and 11 which provides a noveldetachment arrangement that leaves the discharge line 43 insubstantially its normal operating position while the casing sectionsare separated.

The connector 44 of FIG. 1 comprises a plate member 44a having a flangedopening 45 on which the end of a discharge line, such as 43, isattached. When installed, screws 46 and 46a are inserted throughopenings 47 in the plate to clamp it onto the projected ends ofdischarge sections 3411 and 34b. As shown in FIGS. 8, 10 and 11, plate44a has an arm or outboard portions 44x at opposite sides for thesupport of two eccentric lifting assemblies.

Each said assembly as shown in FIG. 9 comprises a threaded pivot pin 48in a bore of outboard portion 44x and extending into threaded engagementwith a nut 49 having an eccentric portion 50 mounted in bearings 52 andextending to a square head section 49a. During pump operation, the heads49a are disposed in a position in which the eccentric portion 50 hasallowed plate 44 to be in pressure contact with a flanged liner member34x, of rubber or the like, and projecting surfaces on the bottom 44z ofplate 44a depress the elastic liner material sufiiciently to form aneffective pressure seal as shown in FIG. 11 when bolts 44 and 46a havebeen tightened. When the sections are to be separated, heads 49a areturned to change the eccentric position which lifts bottom 44z to aposition in which itclears the top of liner 34x as shown in FIG. 10. Theeccentrics 50 are locked in this position by nuts 49.

FIG. 3 illustrates the separated position of pump components and theimpeller 53 has been shown detached from its threaded support positionat the threaded end of shaft 40 interiorly of easing section 23b to showthe arrangement of parts. In such position of the casing members,liners, impeller and other interior parts of the pump are visible, andmay be replaced or repaired as required. When the inspection or repairis completed and all parts are in place, the impact wrench is applied tonut 20 to wind the screw in the opposite direction and thereby movesection 23b into mating contact with section 23a to permit reassembly ofthe pump. Referring .to FIG. 4, there is shown an embodiment with themembers separated and which is preferably used for larger pumps withone-piece volutes. A bed 60 has upstanding side members which support amovable platform member 61 and a fixed platform member 69 each havingflanged guide portions fitting over the upstanding side members of bed60. Platform member 61 supports a pump pedestal 62 which in turnsupports a rotatable shaft 63 and a motor platform 65. Platform member69 supports a pedestal 64 which in turn supports a pump casing 67. Pumpcasing 67 has an inlet flange portion with an associated connectingplate bolted thereto, generally indicated by numeral 67a, and an outletflange portion with an associated connecting plate generally indicatedby numeral 67b. These members connect to liquid transport lines (notshown). A replaceable side cover 66 is supported on pedestal 62 near oneend of shaft 63 and fits into the pump casing 67 in a sealedrelationship during normal operation. An impeller 68 which is shownsuspended between the side cover 66 and pump casing 67 fits on the endof shaft 63 by threading or keying during normal operation. Wheninspection or replacement is required, the platform 61 is moved to theleft by suitable mechanical means, such as the screw drive discussed inFIG. 1. This movement opens the interior of the casing 67, permittingremoval of impeller 68 as shown and allows complete servicing thereof.

FIG. 5 illustrates an embodiment similar to FIG. 4 which is particularlysuitable for large motors which can only be mounted adjacent the pumpinstallation. A bed 70 has upstanding side members which support a fixedplatform member 71 and a movable platform member 79 each having flangedguide portions fitting over the upstanding side members of bed 70.Platform member 71 supports a pump pedestal 72 which in turn supports arotatable shaft 73. Platform member 79 supports a pedestal 74 which inturn supports a pump casing 77. Pump casing 77 has an inlet flangeportion with an associated connecting plate bolted thereto generallyindicated by numeral 77a and an outlet flange portion with an associatedconnecting plate generally indicated by numeral 77b. These membersconnect to liquid transport lines (not shown). A replaceable side cover76 is supported on pedestal 72 near one end of shaft 73 and fits intothe pump casing 77 in a sealed relationship during normal operation.

An impeller 78 which is shown suspended between the side cover 76 andpump casing 77 fits on the end of shaft 73 by threading or keying duringnormal operation. When inspection or replacement is required, platform79 is moved to the right by suitable mechanical means, such as the screwdrive discussed in FIG. 1. This movement opens ptunp casing 77 as shownin FIG.

5. In this embodiment it is necessary to disconnect the inlet anddischarge lines.

. An alternative line connector suitable for use with the outlet line isillustrated in FIGS. 6 and 7.' Pump casing portions 81a and 81b supportsectional liner members 82.

The sectional liner members are designated in FIG. 6 by a single numeral82 because they comprise two identical members which fit together asshown by the divided line in sealed relationship within the pumpcasings. Line connector 83 is fastened to the pump casings by bolts 84a,84b, 87a and 87b. Bolt 84a is fastened to connector 83 by a collar 85aand pin 86a. Bolt 84b has a similar collar and pin combination (notshown). Bolts 87a and 87b have no locking collars but are removedallowing the pump casing 81b to slide with the movable platform whenthis connector is used with the outlet line. Rotation of bolts 84a and84b separates connector 83 from casing portions 81a and 81b to break theseal therebetween and allow casing portion 81b to move with the movableplatform similar to member 23b as shown in FIG. 3.

This connector arrangement is conveniently usable on the discharge lineand provides a fast means of breaking the seal between the pump casingand the connector cap so as to elevate the line connector and dischargeline. The bolts which remain in the connector cap and pump casing keepthe components in line for quick reassembly after servicing.

While particular embodiments have been shown and described, it isdistinctly understood that the invention is not limited thereto but thatmodifications may be made within the scope of the invention, and suchvariations are covered by the scope of the appended claims.

We claim:

1. A pump assembly comprising a volute casing having an upright flangedoutlet portion and a flanged inlet portion distant therefrom adapted forconnection with outlet and inlet fluid transport lines, said casingbeing split into a pair of casing sections, a bed member adapted to besecured on a supporting structure and inclusive of a pair of spacedupright side rails, a platform covering the space between said siderails and having guide portions extending downwardly over the upperportion of said side rails in slip-fitting relationship, said platformbeing split into a pair of platform sections with one platform sectionmovable over the side rails toward and away from the other platformsection in alined relationship, a pedestal member secured on eachplatform, one said pedestal member disposed in supporting connectionwith one casing section, the other said pedestal member supporting theother casing section and shaft drive means including a shaft extendinginto the volute casing, an impeller mounted for rotation on the end ofsaid shaft within the volute casing, and means for moving the movableplatform section toward and away from the other platform section toseparate the casing between its sections for inspection and repair ofthe pump.

2. A pump assembly comprising a volute casing having an upright flangedoutlet portion and a flanged inlet portion distant therefrom .adaptedfor connection with outlet and inlet fluid transport lines, said casingbeing split into a pair of casing sections through the outlet portion, abed member adapted to be secured on a supporting structure and inclusiveof a pair of spaced upright parallel side rails, a platform covering thespace between said side rails and having guide portions extendingdownwardly over the upper portion of said side rails in slipfittingrelationship, said platform being split into a pair of platform sectionswith one platform section movable over the side rails toward and awayfrom the other platform section in alined relationship, a pedestalmember secured on each platform, one said pedestal member disposed insupporting connection with one casing section,

the end of said shaft, a block having threads on the interior thereofmounted on the bed member below said platform, and a screw memberthreaded into said block and attached to the underside of the movableplatform section at each end for moving the movable platform sectiontoward and away from the other platform section to separate the casingbetween its sections for inspection and repair of the pump.

3. A pump assembly comprising a volute casing having an upright flangedoutlet portion and a flanged inlet portion adapted for connection withoutlet and inlet fluid transport lines, said casing being split into aside cover section and a volute section, a bed member adapted to besecured on a supporting structure and inclusive of a pair of spacedupright side rails, a platform covering the space between said siderails and having guide portions extending downwardly over the upperportion of said side rails in slip-fitting relationship, said platformbeing split into a pair of platform sections with one platform sectionmovable over the side rails toward and away from the other platformsection in alined relationship, a pedestal member secured on eachplatform, the movable pedestal member disposed in supporting connectionwith said volute section, the other pedestal member supporting said sidecover section and shaft drive means including a shaft extending into thevolute casing, an impeller mounted for rotation on the end of said shaftwithin the volute casing, a block having threads on the interior thereofmounted on the bed below said platform, and a screw member threaded intosaid block and attached to the underside of the movable platform sectionat each end for moving the movable platform toward and away from theother platform section to separate the casing between its sections forinspection and'repair of the pump.

4. A pump assembly comprising a volute casing having an upright flangedoutlet portion and a flanged inlet portion adapted for connection withoutlet and inlet fluid transport lines, said casing being split into aside cover section and a volute section, a bed member adapted to besecured on a supporting structure and inclusive of a pair of spacedupright side rails, a platform covering the space between said siderails and having guide portions extending downwardly over the upperportion of said side rails in slip-fitting relationship, said platformbeing split into a pair of platform sections with one platform sectionmovable over the side rails toward and away from the other platformsection in alined relationship, .a pedestal member secured on eachplatform, the movable pedestal disposed in supporting relation with saidside cover section and shaft drive means including a shaft extendinginto the volute casing, the other pedestal member disposed in supportingconnection with said, volute section, an impeller mounted for rotationon the end of said shaft within the volute casing, a block havingthreads on the interior thereof mounted on the bed below said platform,and a screw member threaded into said block and attached to theunderside of the movable platform section at each end for moving themovable platform toward and away from the other platform section toseparate the casing between its sections for inspection and repair ofthe pump.

5. A pump assembly comprising a volute casing having an upright flangedoutlet portion and a flanged inlet portion adapted for connection withoutlet and inlet fluid transport lines, said casing being split into aside cover section and a volute section, a bed member adapted to besecured on asupporting structure and inclusive ofna pair of spacedupright side rails, a platform covering the space between said siderails and having guide portions extending downwardly over the upperportion of said side rails in slip-fitting relationship, said platformbeing split into a pair of platform sections with one platform sectionmovable over the side rails toward and away from the other platformsection'in alined relationship, a pedestal member secured on eachplatform, one said pedestal member disposed in supporting connectionwith said volute section, the other pedestal member supporting said sidecover section and shaft drive means including a shaft extending into thevolute casing, an impeller mounted for rotation on the end of said shaftwithin the volute casing, a flexible liner supported in the casingextending through the outlet portion and overlapping the flange of theoutlet portion, a plate member having a sealed connection with theoutlet line, a connector assembly arranged to clamp the overlappingportion of the liner sections between the outlet flange and the platemember in one position and to separate the plate member from the flangeand liner section in the other position, a block having threads on theinterior thereof on the bed member below said platform, and a screwmember threaded into said block and attached to the underside of themovable platform section at each end for moving the movable platformsection toward and away from the other platform section to separate thecasing between its sections for inspection and repair of the pump.

6. A pump assembly comprising a volute casing having an upright flangedoutlet portion and a flanged inlet portion distant therefrom adapted forconnection with outlet and inlet fluid transport lines, said casingbeing split into a pair of casing sections through the outlet portion,one section supported on a stationary base member and the other sectionsupported on a movable base member, a plate attached to said outlet lineto clamp the outlet line to the flanged outlet portion and bolts havingkeyed collars attached to the plate and bolted to the flanged outletportion to raise and release the outlet line upon rotation of the boltsto permit movement of the movable casing section away from thestationary casing section, and means for moving the movable base memberaway from the stationary base member so as to separate the casingbetween the sections for inspection and repair of the pump.

7. A pump assembly comprising a volute casing having an upright flangedoutlet portion and a flanged inlet portion distant therefrom adapted forconnection with outlet and inlet fluid transport lines, said casingbeing split into a pair of casing sections through the outlet portion,one section supported on a stationary base member and the other sectionsupported on a movable base member, a plate member having means forsealed connection with the outlet line, clamping means on said platemember for holding it in liquid sealed relation to the flanged outletportion, an eccentric member arranged for raising the plate from theflanged outlet portion when the movable casing is being moved so as toleave the outlet line in substantially its normal location and forattachment to the flanged outlet portion on its return to the stationaryposition, and means for moving the movable base member away from thestationary base member so as to separate the casing between the sectionsfor inspection and repair of the pump.

8. A pump assembly comprising a volute casing having an upright outletportion and an inlet portion distant therefrom adapted for connectionwith outlet and inlet fluid transport lines, said outlet portion havinga connection with a fluid transport outlet line, said casing being splitinto a pair of casing sections through said outlet portion, one saidsection having a stationary base member and the other section having amovable base member, means on one of said sections for moving themovable section axially toward and away from the stationary section, andmeans engaging the stationary section for raising a portion of saidfluid transport outlet line away from the outlet portion of the movablesection sufliciently to provide clearance therewith, whereby to permitsaid axial movement of the movable section so as to separate the casingbetween the sections for inspection and repair of the pump.

9. A pump assembly as set forth in claim 8 wherein said latter means isoperable to lower the raised portion of the fluid transport outlet lineto its original position.

10. A pump assembly as set forth in claim 8 wherein a separate flexibleliner section is supported in each casing section.

11. A pump assembly as set forth in claim 8 wherein a separate flexibleliner section is disposed in each casing section, each liner sectionextending through the outlet portion and overlapping a flange of theoutlet portion and wherein said latter means is a connector assemblyarranged to clamp the overlapping portion of the liner sections betweenthe outlet flange and the fluid transport outlet line in one positionand to separate the outlet line from the outlet flange and liner sectionof the movable section of the casing in the other position.

12. A pump assembly comprising a volute casing having an upright flangedoutlet portion and a flanged inlet portign distant therefrom adapted forconnection with outlet and inlet fluid transport lines, said casingbeing split into a pair of casing sections, a bed member inclusive of apair of spaced upright side rails adapted to be secured on a supportingstructure, a platform comprising a pair of complemental sections inabutting relationship in a common plane and having guide portionsextending downwardly over the upper portion of said side rails inslip-fitting relationship to completely cover said rails during thenormal operation of the pump whereby the rails are protected againstdeposits of foreign matter thereon, one said platform section disposedin supporting connection with one casing section, the other saidplatform section supporting the other casing section, and one saidplatform section having means for moving over the side rails toward andaway from the other platform section in said common plane to separatethe casing between its sections for inspection and repair of the pump.

References Cited by the Examiner UNITED STATES PATENTS 1,471,559 10/1923Knauf 103-111 2,265,940 12/1941 Forrest 103-111 2,849,960 9/1958Olmstead et a1. 103-111 2,853,018 9/1958 Stark 103-111 2,874,642 2/1959Forrest 103-115 3,022,740 2/ 1962 Wilfley et al. 230-133 3,094,0756/1963 Logue 103-114 3,131,642 5/1964 Geer et al. 103-114 FOREIGNPATENTS 113,706 9/1941 Australia.

652,423 4/ 1928 France.

163,019 6/ 1921 Great Britain.

SAMUEL LEVINE, Primary Examiner.

HENRY F. RADUAZO, Assistant Examiner.

1. A PUMP ASSEMBLY COMPRISING A VOLUTE CASING HAVING AN UPRIGHT FLANGEDOUTLET PORTION AND A FLANGED INLET PORTION DISTANT THEREFROM ADAPTED FORCONNECTION WITH OUTLET AND INLET FLUID TRANSPORT LINES, SAID CASINGBEING SPLIT INTO A PAIR OF CASING SECTIONS, A BED MEMBER ADAPTED TO BESECURED ON A SUPPORTING STRUCTURE AND INCLUSIVE OF A PAIR OF SPACEDUPRIGHT SIDE RAILS, A PLATFORM COVERING THE SPACE BETWEEN SAID SIDERAILS AND HAVING GUIDE PORTIONS EXTENDING DOWNWARDLY OVER THE UPPERPORTION OF SAID SIDE RAILS IN SLIP-FITTING RELATIONSHIP, SAID PLATFORMBEING SPLIT INTO A PAIR OF PLATFORM SECTIONS WITH ONE PLATFORM SECTIONMOVABLE OVER THE SIDE RAILS TOWARD AND AWAY FROM THE OTHER PLATFORMSECTION IN ALINED RELATIONSHIP, A PEDESTAL MEMBER SECURED ON EACHPLATFORM, ONE SAID PEDESTAL MEMBER DISPOSED IN SUPPORTNG CONNECTION WITHONE CASING SECTION, THE OTHER SAID PEDESTAL MEMBER SUPPORTING THE OTHERCASING SECTION AND SHAFT DRIVE MEANS INCLUDING A SHAFT EXTENDING INTOTHE VOLUTE CASING, AN IM-